Study on metabolism of N-Butyl Benzyl Phthalate (BBP) and Dibutyl Phthalate (DBP) in Ctenopharyngodon idellus by GC and LC-MS/MS

Abstract

To deeply study the toxic effect and mechanism of Dibutyl Phthalate (DBP) and Butyl Benzyl Phthalate (BBP) in fish, their in vivo and in vitro metabolism was investigated in this study. At first, a gas chromatography method was developed for simultaneous determination of DBP and BBP in blood serum, hepato-pancreas homogenate, intestine homogenate and hepatocyte medium. Then the main metabolites of the two PAEs chemicals were identified in Ctenopharyngodon idellus tissues by HPLC-MS/MS. And the results showed that DBP and BBP were metabolized quickly in blood serum, intestinal tract and hepato-pancreas homogenate, especially in the serum and the main metabolites were monobutyl phthalate (mBP) and monobenzyl phthalate (mBzP). However, they were not metabolized significantly in hepatocyte medium and the main metabolites in urine were the corresponding mono-phthalates and their conjugates of glucuronic acid. These studies indicated that DBP and BBP were hydrolyzed into mono-esters in some tissues in varying degrees, which were metabolized into corresponding conjugates combined with glucuronic acid later, and that will contribute to the elimination of PAEs from C. idellus. The blood and intestine were the first metabolized location of PAEs chemicals absorbed through fish’s gill and intestine. Key words: Ctenopharyngodon idellus, PAEs, GC, LC-MS/MS.